Flexible power-transmitting device



C. H. AU.

FLEXIBLE POWER TRANSMITTING DEVICE.

APPLICATION FILED MAY I6, l9l9.

Patented Feb. 17,1920.

2 SHEETS-SHEET l NNl l m C. H. AU.

FLEXIBLE POWER TRANSNHTTING DEVlCE.

APPLICATION min MAY \5, |919.

1,83 1 ,3 1 1 Patented Feb. 17, 1921 2 SHEETS-SHEET 2.

\`\ @www/woz CAN@ "1% OMM @www o@ Q :se WLWCWWVMMw-rmm CARL H. AU, OF WASHINGTON, DISTRICT 0F COLUMBIA.

FLEXIBLE POWER-TRANSMITTING DEVICE.

Specication of Letters Patent Patented Feb. 17, 1920.

Application led May 16, 1919. Serial N o. 297,486.

To all whom t may concern Be it known that I, CARL H. AU, a citizen of the United States of America, and a resident of Washington, District of Columbia, have invented a new and useful Improvement in Flexible Power-Transmitting Devices, which invention is fully set forth in the-following specification.

The present invention relates to improve ments in ieXible power-transmitting devices, and more particularly to devices of the above class suitable for applying power to release devices such as photographic shutters, or for operating automobile horns or other devices to which power is applied through a flexible shaft.

Heretofore flexible power-transmitting devices have been constructed with an inner inextensible cable and an outer incompressible tube. The power in all such cases has been transmitted through the movement of the inner cable by either a thrust which tends to buckle the cable inside its tubular casing stretching the latter and interfering with the usefulness of the transmission device, or by a manual pull On the inner cable which limits the field of usefulness of the device and practically excludes its employment on cameras used 1n aerial photography at highl elevations where the temperature is low, and tractible hand manipulation diflicult or impossible.

My invention overcomes the above. objections and resides in providing an inner inextensible tension member such as a wire cable having means at one -Or both ends for attachment, and an outer flexible incompressible member suoli as a tube formed of.a helical metal ribbon movable over the tension inemloer and provided wit-h means at one end for applying its powerbeyond one of the attaching means of the tension member. This latter means preferably consists of a plunger working in a tubular casing and is yieldingly held between the end of the power member and the tubular casing to which one end of the tension member is secured. By reason of the above construction wherein the inner element is a tension member, and the outer `element is an integral.' compression member, there is no lost motion between the .parts and the resultant effect is a thrust applied beyond the point of attachment of the tension member.

In order that my invention may more vbar 13 fast to the latter.

readily be understood, reference is had to the accompanying drawings which illustrate by way of example one constructional form thereof and are intended to assist. the description of the invention but not to limit its scope.

Figure l is a side view of a flexible powertransmitting device constructed in accordance with my invention, a portion of the flexible transmitting section having been cut out.

Fig. 2 is a central longitudinal sectional view of the device taken on the line 2 2 of Fig. l showing the position of parts when in normal position of rest.

Fig. 3 is a similar sectional view of Fig. 2 showing the parts in operative position.

Figs. 4, 5 and 6 are detail views.

Fig. 7 is a general view showing the application of my improvement to the operation of a shutter in an aerial camera..

Figs. 8 and 9 are enlarged detail views.

Referring more particularly to Figs. 1, 2 and 3 of the drawings, 1 is a cylindrical casin provided -with means, such as a threa ed neck portion 2, for attachment to any suitable abutment. lVithin casing l plays a hollow plunger 3 provided with a shoulder portion t adapted to retain a spring 5 normally tending to restrain the plunger from outward movement. Fitting the interior of plunger 3 is a head 6 which is made. fast to casing l by means of a pin 7 which passes through slots 8 formed in the walls of the plunger 3. To head 6 is secured one end of a iieXible ineXt-ensible tension member such as a wire cable 9 and to plunger 3 is secured one end of an incompressible power member, such as a helically-wound metal tube l0.

For the purpose of anchoring the opposite end of cable 9, when desired, any suitable means may be provided. Illustrative of one such means, I have shown a head-piece l1 to which the outer end of the cable 9 is secured by solder. This head is cent-rally held within an annular plate l2 by means of a In Figs. 7 and 8 this plate is shown mounted on a bracket 13 secured to the framing of an airplane. The power-receiving end of the flexible powermember 10 is secured to a tube 15 adapted to receive the head 1l and is provided with opposite slots 16 which receive the bar 13 and permit free play of the tube over the head 11 and bar 13. The outer end of the tube is provided with a knob 17 and secured in position by a pin 18.

Assume that the device is to be used for operating the sliutter-release means of a camera, and that the latter is to be mounted for aerial photography on an airplane as shown in Fig. 7 The arts of the device are assembled as shown in Fig. 2. The cylinder 1 is made fast to a part of the cameral by screwing the neck 2 into a suitable support such as a threaded socket 19 (Fig. 7) fast to the camera Wall. The .hand-operating end of the transmission is supported on the framing of the airplane in easy reach of the photographic observer. When the device is thus supported, the ends 1 and 12 (Figs. 9 and 8) of the tension member 9 are anchored' to stationary members 19 and 14 and the power-transmitting member 10 is adapted to be moved over the cable, the ends of the latter being supported in the plunger 3 and tube 15 respectively.

By reason of this construction the inner Wire cable becomes a stationary tension element and the outer incompressible movable element 10 becomes the power-transmitting element or thrust element. A direct push by the hand or a blow of' the fist on the knob 17 is transmitted through the flexible outer incompressible thrust member 10 to the plunger 3 which is forced out of its casing against the tension spring Spring 5 returns the parts to their original positions.

It will be observed from the above that the outei flexible element moves over the inner stationary element ofl the flexible transmission, thereby obviating the endwise compression of a flexible element inside a tube andthereby preventing buckling and obstruction by the power element and further that the thrust on the outer flexible element is through an integral element and is transmitted beyond the anchoredend of the tension element and in axial alinement with the tension element. thereby retaining the advantages of axial alinement and also dispensing with levers and their attendant lost motion. 1

What is claimed is:

1. In a flexible power-transmittiiig device, the combination of a flexible iiiextensible tension member provided with end abutments, a tubular, flexible, incompressible, power-transmitting member movable over said tension member and provided at one end with a plunger for applying an outward thrust beyond one end of said tension member, and yielding means normally restraining movement of said plunger.

2. In a flexible power-transmitting device, the combination of a flexible, iiiextensible tension member and a tubular flexible, incompi'essible power-transmitting member movable over said tension member, means for anchoring one end of said tension meniber, and a power-delivering element yieldingly held between the end of said tubular poWer-traiismittiiig memberl and said anclioring means, for applying power beyond the anchored end of said cable.

3. In a flexible power-transmittiiig device, the combination `of a flexible inextensible tension member and a tubular, flexible, incompressible, power-transmitting member movable over said tension member and provided with a plunger'for applying' power beyond the end of said tension member, a tubular casing to which one end'of said tension member is anchored and in' which said plunger works, and yielding means normally restraining the longitudinal movement of said flexible power member.

l. In a flexible power-transniitting device, the combination of' a flexible, inextensible tension member and a tubular, flexible, incompi'essible power-ti'ansmitting member movable over said tension member, a tubular casing to which one end ofpsaid tension member is anchored, a power-'delivering plunger working in said casing and yieldingly held between one end of said flexible power member and said casing for delivering power beyond the anchoring point of said tension member.

5. In a flexible power-t ansmitting device. the combination ofl a flexible, inextensible tension member 'and a tubular, flexible. incompressible powertransmitting member movable over said tension member and provided with a plunger for applying power beyond the end of said tension member. means for anchoring one end of said tension member, yielding means normally restraining the longitudinal movement of said flexible power member and a manual thrust member secured to one end of said tubular, flexible power member.

In testimony whereof I have signed this specification.

CARL H. AU. 

